Aminopeptidase N (CD13) Is Involved in Phagocytic Processes in Human Dendritic Cells and Macrophages
Figure 2
CD13 cross-linking enhances phagocytosis of zymosan by MD-DCs and MD-Ms. Cells were incubated with F(ab′)2 fragments of mAb 452 (anti-CD13) at 4°C. After washing, the cells were incubated with 20 μg of zymosan-FITC in the presence (CD13xl) or absence of F(ab′)2 fragments of goat anti-mouse antibodies for 60 min (MD-DCs) or 30 min (MD-Ms) at 37°C. The phagocytic index (a) (geometric mean of fluorescence intensity multiplied by the percentage of positive cells) and the percentage of fluorescence positive cells (b) (% of phagocytosis) were determined using flow cytometry. Data were normalized considering the value obtained in the absence of CD13 cross-linking as 100%; for MD-DCs and for MD-Ms. *. Histograms of a representative experiment with MD-DCs (c) and MD-Ms (d): dashed lines: cells incubated with zymosan at 4°C; gray lines: cells incubated with zymosan at 37°C; black lines: cells incubated with zymosan at 37°C in the presence of CD13 cross-linking. In this experiment, the percentages of CD14+ cells were 96% in MD-Ms and 16% in MD-DCs, and the percentages of CD1a+ cells were 18% in MD-Ms and 93% in MD-DCs.
